Voltage at pin 25 measured at +4.760 volts.

Good help there, I checked out F3 and it's got continuity. "L10 L9 L8 D3 F3, ... D3, 1N4001." that got me lost. L10 is a reference point on the board? as are L8 and L9, I couldn't find D3 (there's D2 on the top of the board by the PRAM battery, and D4 underneath, and those are transistors).

EDIT: According to Apple's KB article link Pin 26 should be Internal HDD Termination power. I assume that if voltage was detected at DB-25 then no internal test is required?